Device for removing molten metal



Dec. 6, 193s.

l. J. B. DEMERS DEVICE FOR REMOVING MOLTEN METAL Filed July 31, 1937 Imam/bom Patented Dec. `6, 1938 UNITED STATES PATENT oFFlcE DEVICE FOR REMOVING MOLTEN METAL Application July 31, 1937, Serial No. 156,694

5 Claims.

It is an object of this invention to provide a novel device for removing the excess of molten plating material from the interior of a container, the invention being particularly, although not exclusively, adapted for use in the Method of hot plating containers described and claimed in my application for Letters Patent of the United States bearing Serial No. 107,601, filed October 26, 1936 now Patent 2,105,906.

Another object is to provide a device adapted to be inserted through a restricted opening in a can, tank or other container to reach and Withdraw, at the proper instant, the accumulation of plating material which flows to the lowest point in the container as the container cools.

A particular object is to provide a device of this kind for use in a hot plating process wherein the thickest plating is located on the bottom and adjacent parts of the containers and wherein containers having imperforate bottoms are allowed to cool and the plating allowed to harden while retaining the containers in upright or normal position.

Other objects will appear and be more fully pointed out in the following specification and claims.

In the manufacture of many types of sheet metal containers, such for example as those used for dairy products, it is desirable, in the interest of economy and to avoid unsightly and unsanitary joints, to weld the bottoms to the walls before the plating operation. When this is done, however, the problem of obtaining the proper distribution of the plating material to impart maximum durability to the container is rendered more diicult, particularly where the finished containers have no bottom opening which can be utilized as an outlet for the excess of plating material during the progressive cooling of the containers. By the device described and claimed herein I eliminate the necessity for an opening or perforation in the bottom of the container and at the same time secure the advantages of increased thickness of plating material on the bottom and lower portions of the walls of the 4containers and I also eliminate all unsightly metal drippings and such non-uniformity in the distribution of the metal on the container as commonly result from decanting the excess through a top opening in the container.

Referring to the accompanying drawing:

Figure l is a side elevation of my improved device and illustrating the method of using it in connection with the plating of. a milk can, the

` latter, together with a listing table supporting Fig. 3 isa plan view of the head of the device, and

Fig. 4 illustrates the head in the position in which it is held or placed for emptying the plating material.

My device has a hollow head, indicated generally by the numeral 5, into which the pool of excess plating material may be drawn through a pendant intake tube 6 which is open at its lower end and communicates with the interior of the head 5. The bottom of the head 5 slopes obliquely down from the periphery where the tube 6 is attached to form a trap in which the excess of plating material 8 is collected. Rigidly secured to the top of the head 5 is a pipe 9 which communicates with the interior of the head 5 and with a exible, air hose I0. This hose extends to a suitable suction device (not shown) adapted to exhaust air from the hose, pipe 9 and head 5 when it is desired to draw molten metal into the head 5 through the inlet tube 6. To prevent particles of solid matter from entering the hose I0, a body Il of porous ltering material is located in the connection between the hose III and pipe 9. pipe 9 is a nipple I2'which has a top opening that may be closed by the hand of the operator when it is desired to create reduced pressure in the head 5. l

I provide a heater for maintaining the head 5 at sufficiently elevated temperature to retain any plating material therein in molten condition. The heater consists of a small tube I3 supplying a mixture of combustible gas and air to a burner I4 arranged to direct a'ame I5 against the head v 5. The tube I3 is attached to the pipe 9 by small clamps I6 and is suiciently flexible to permit manipulation of the device.

At one side of the top of the head 5, an outlet passage I1 is formed. This passage is normally closed by a flap valve I8 pivoted on a pin I9 in such position that the valve is closed when the pipe 9 is vertical and opens by gravity when the head 5 is to be emptied, as indicated in Fig. 4. The passage II is preferably located directly opposite or in alignment with the upper end of the tube 6 so that the passage I'I allows ready access to the tube E for cleaning.

The device is illustrated in connection with a milk can, indicated generally by the numeral 20, having its several parts joined together by welding. An internally concave bottom 2l has its periphery welded to the cylindrical walls of the can 20 and is preferably formed with a small indentation 22 at the centralpoint of the bottom to receive the iinal increment of excess plating material. The container 20 is without perforations in its bottom so that the excess plating material cannot escape by gravity when the container is in upright position.

Also communicating with the As shown in Fig. 1, during the process of hot plating the container 2D it is placed in upright position on a listing table 23 comprising a foraminous horizontal plate supported within the top of a kettle or vat 24 containing a body 25 of plating material. in molten condition by heating. Suitable burners for heating the metal in the vat 24 arey well known in this art and are shown diagrammatically in the drawing, being indicated by the numeral 26. The solidified plating on'the can 2U is indicated by the numeral 21.

Operation As a preliminary to the plating or tinning of a container, it is thoroughly cleansed,v usually in an acid` bath. It is now immersed in a bath of the molten plating material so that the latter completely covers the inside and outside surfaces of the container. Two or more immersions are usually required. After the final immersion in the plating material the greater part of the excess is decanted from` the top of the container. This is done before the plating on any part of the container has solidified and then the container is supported in upright position, as indicated in Figs. 1 and 2 of the drawings, while the plating cools and hardens. The surface of the metal in the kettle or vat 24 `is maintained slightly above the listing plate 23 so that the lower extremity of the container 20 rests in the hot metal while the excess of plating material from the exterior of the container flows into the vat 24. f

While thus positioned on the listing table, the container 20 cools progressively from the top down and the excess of plating material from the interior surfaces collects in a small pool centrally on the bottom 2 I, in and around the depression 22 in cases Where the latter is provided. The central portion of the bottom 2| is the'last interior part of the container to cool sufficiently for the hardening of the plating material. While this accumulation or pool of metal is still in molten condition, the operator inserts my device through the top opening in the container 20, as indicated in Fig. 1, placing the intake tube 6 in the depression 22 or at the central point of the bottom of the container. Just before the pool hardens, the operator closes the upperend of the nipple I2 with his thumb. This causes the air to be exhausted from the head 5i through the pipe 9 and hose I0 with the result that the accumulau tion of plating material is drawn into the head 5. The device is then withdrawn from the container, leaving a perfectly smooth plating surface therein, without contacting any of the cooled portions of plating. Finally the plated' container 20 is removed from the listing table 23 and the head 5 is so placed that the entrapped vplating material 8 is decanted through the passage I1, as indicated in Fig. 4. It will be understood that the head 5 is continuously heated by the flame I5 to such temperature as toliquefy the plating material contained in the head. The passage I1, being located in alignment with the inner end ofthe tube 6, affords easy access to the restricted inlet passage from which oxidized plating material must be periodically removed to keep the tube 6 open. To remove solid matter, such as the oxidized metal from the interior of the head 5, a

This material is maintained,

wire rod or other suitable tool is inserted through the passage I1.

By locating the tube 6 at one side of the head 5 and with the inlet end of the tube projecting where it is visible through the top opening in the container 20, I facilitate the accurate placing of the device in the molten pool to be withdrawn. All drippings and spilling of the excess plating on the cooled surfaces of the container are eliminated by my device and unusually smooth, uniform plating is secured on the bottom surfaces from which the excess plating material has been withdrawn.

A substantial saving of plating material and the desired distribution with the thicker coating on the lower portion of the container, so that it affords the greatest protection where most needed, are further advantages obtained by the use of my device.

Having described my invention, what I claim as new and desire to protect by Letters Patent is:

l. A device for removing pools of molten metal from the interior surfaces of containers in the process` of hot plating the same comprising, a hollow head adapted to be inserted through an opening in a container, an inlet passage for molten plating material communicating with the interior of said head and projecting downwardly therefrom and means for creating suction in said head.

2. A device for removing pools of molten metal from the interior surfaces of containers in the process of hot plating the same comprising, a hollow head adapted to be inserted through an opening in a container, an inlet passage for molten plating metal communicating with the interior of said head and having an intake opening at its lower extremity, a suction pipe extending upwardly from said head and means for heating said head to maintain plating metal therein in molten condition.

3. A device of the class described having in combination, a hollow head adapted to be heated, an inlet passage for molten metal communicating with said head and having an inlet end formed to receive molten metal from a shallow pool in the bottom of a container, a suction pipe extending upward from said head and communicating with the interior thereof and a trap cham ber formed in the bottom of said head to receive molten metal from said inlet passage.

4. A device of the class described comprising, a hollow head adapted to be inserted in a container, an inlet pasasge formed in said head to receive molten metal from a pool in the bottom of said container, a suction pipe communicating With said head, an outlet passage for molten metal formed in said head and a closure for said outlet passage.

5. A device of the class described comprising, a hollow head adapted to be inserted through a restricted opening in a container, an inlet passage communicating with the interior of said head and having a lower extremity adapted to receive molten metal from a pool in the bottom of said containenmeans for creating suction in said head, a trap chamber formed in the bottom of said head to receive metal from said inlet passage, and means for heating said head to maintain plating metal therein in molten condition.

vISAI J. B. DEMERs. 

